Electrical connector assemblies of the locking type are well known in the connector industry. Normally, the female portion of such a connector assembly is provided with three or more arcuate circularly arranged slots, and the male portion is provided with an equal number of slightly arcuate blades, the blades being dimensioned and arranged so that they can be inserted in the slots by simple axial movement of the male connector body and then, by rotation of one or both of the connector portions, the blades are moved into a position from which they cannot be separated by simple axial movement. One or more of the blades usually has an L-shaped configuration such that the laterally extending portion of the L engages a recess within the slot as a result of the rotation.
The male and female portions can take various configurations, but the male portion is usually a plug connected to the end of a multi-conductor cable. The female portion may also terminate a similar cable, or it can be a fixture mounted in a partition or on a piece of equipment. In any event, it is possible for the cable attached to the male portion to be subjected to various forces which might tend to rotate the cable, and also the male connector portion, in the unlocking direction, thereby causing inadvertent unlocking and extraction of the blades from the slots.
To prevent this kind of undesired extraction, there has been an effort to develop connectors which have greater resistance to accidental disconnection or which have locking devices capable of precluding such accidental disconnection. Examples of locking connectors and connectors having supplemental locking devices are found in the following U.S. Patents.
______________________________________ 2,684,860 Rafferty 2,750,571 Schmier 3,120,987 Degnan et al 3,390,404 Murchison 3,393,395 Hubbell 3,500,291 Hubbell et al 3,739,321 Murphy et al 3,790,914 Hough 3,888,559 Geib 3,890,025 Gray 3,950,059 Anhalt et al ______________________________________
A particularly good example is found in U.S. Pat. No. 3,500,291 which includes a connector having locking blades and also a retractable pin. The pin protrudes from the face of the male connector portion, parallel with the blades, and in the fully engaged, locked position, enters a slot behind a blade which it follows, protruding into the face of the female portion. To detach the two connectors, the male connector portion is provided with an axially movable sleeve coupled to the locking pin. One simply moves the sleeve axially, thereby retracting the locking pin from the slot, and then rotates the male connector portion in the unlocking direction (counter-clockwise, as shown in the patent, and as normally constructed) and then, by a further axial movement, withdraws the blades from the slots.
While this is a fully satisfactory arrangement insofar as the locking function itself is concerned, it presents certain difficulties. As will be recognized, in order to detach the two connector portions from each other, one must know in advance that it is necessary to perform three separate movements in different directions, i.e., axial, then rotational, then axial. One unfamiliar with the specific type of connector can be temporarily baffled by his inability to accomplish separation by either axial or rotational movement, a condition which could lead to unfortunate results in the event of an urgent need to separate the connectors.
Furthermore, in circumstances where the connector is to be exposed to severe weather conditions or moisture and is therefore to be provided with a protective elastomeric cover, it is quite difficult to provide a cover which is sufficiently sturdy to provide the necessary weatherproofing and, concurrently, sufficiently flexible in multiple directions to permit the sequence including both axial and rotational movement. Thus, the use of such connectors is somewhat limited.